Thread: modular modular case
Actually I only know those ones
Fraptools Plug: not really "modular"
KAHNCO Modular: the best one I've found, but the guys don't respond to emails
and there's no place to purchase it...probably never launched
http://www.kahncomod.com
SP-1: the only real modular-modular case
https://www.matrixsynth.com/2019/01/the-sp1-eurorack-case-modular-3d.html
do you know other similar projects?